replacing umlaute and fixing address in headers Haldeneggsteig -> Universitaetsstrasse

Signed-off-by: Reto Achermann <reto.achermann@inf.ethz.ch>

net_sockets: move defines to seperate header file

Preparation to implement net_socket server as driver moduel
so it can run within the same domain as the driver

Signed-off-by: Roni Häcki <roni.haecki@inf.ethz.ch>